#include <iostream>
#include <conio.h>
using namespace std;
int main()
{
  float N;
  float S;
  S=0;
  cout<<"vvedi chislo N: ";
  cin>>N;
  for (float i=1; i<N+1;i++)
  {
      S=S+1/i;
  }
  cout<<S<<endl;
  getch();
  return 0;
}
